1. Field of the Invention
The present invention relates to a pipe rehabilitation method for installing a rehabilitation pipe inside an existing pipe using segments each of which comprises an inner surface plate constituting an inner circumferential surface, and side plates and end plates provided upright on peripheral edges of the inner surface plate, these plates being formed integrally from a plastic material and linked in the circumferential direction and in the pipe-length direction.
2. Description of the Related Art
In cases in which a sewage pipe or another pipeline buried underground has deteriorated through aging, a pipe lining method has been proposed and practiced in which a lining is provided to the inner circumferential surface thereof to repair the pipeline without excavating it from the ground.
In this pipe lining method, a pipe lining material made of a tubular resin absorbent material impregnated with an uncured thermosetting resin is everted and inserted into a pipeline using fluid pressure, and is pressed by fluid pressure against the inner peripheral wall of the pipeline. The lining material is then heated using a desired method to cure the thermosetting resin therein and form a plastic pipe, thereby repairing the pipeline.
There is also known a lining method using segments each comprising an inner surface plate constituting an inner circumferential surface, side plates and end plates provided upright on the peripheral edges of the inner surface plate, these plates being integrally formed from a plastic material. The segments are linked in the circumferential direction to assemble short pipe units, which are then linked in the pipe-length direction to construct a rehabilitation pipe inside an existing pipe (for example, JP-A 2011-12803). Such a pipe rehabilitation method is used for large-diameter existing pipes. In this method, after assembling a rehabilitation pipe inside the existing pipe, grout or another filler material is injected into a space between the existing pipe and the rehabilitation pipe and hardened to construct a composite pipe.
In the rehabilitation pipe described in JP-A 2011-12803, segments are successively carried into a manhole and coupled in the circumferential direction to assemble a pipe unit. A plurality of nuts are secured to each segment of the assembled pipe unit, and the pipe units with the nuts secured thereto are brought into contact with each other. A bolt is inserted into the segment of one pipe unit and screwed into the nut secured to the segment of the other pipe unit to fasten both segments together, thus linking both pipe units in the pipe-length direction.
However, the bolts are inserted into the segment and tightened at a dark site by an operator. This makes the rehabilitation operation more complex and inefficient, necessitating time and labor.
It is therefore an object of the present invention to provide a pipe rehabilitation method that is capable of easily linking the segments in the pipe-length direction to reduce labor during pipe rehabilitation operations.